OLLI WEST: EARTH CLIMATE – WEEK 3 Paul E. Belanger, Ph.D. FIELD TRIP: NATIONAL ICE CORE LAB Tuesday September 30, 2014

SPECIAL THANKS TO OUR HOST(s): Richard Nunn and other personnel in the Ice Core Lab FIELD TRIP: NATIONAL ICE CORE LAB Tuesday September 30, 2014 OLLI WEST: EARTH CLIMATE – WEEK 3

DATA Western Interior Paleontological Society

EMPIRICAL DATA ACTUAL MEASUREMENTS: ATMOSPHERIC COMPOSITION, STABLE ISOTOPES, % CO3, ASSEMBLAGE INFORMATION, ETC.

EMPIRICAL DATA SOME OF THIS DATA YOU CAN’T DO MUCH WITH ONE NEEDS TO INTERPRET WHAT IT MEANS THAT THEN MAKES IT “PROXY” DATA

“PROXY” DATA DATA BY WHICH WE MAKE INTERPRETATIONS

EARLY PROXY DATA: TREE RINGS Interpretation: dry or wet periods of time

PROXY DATA: LEAVES Interpretation: Climatic regime: tropical, boreal, etc.

Deep Sea Coring Ruddiman, 2008

PROXY DATA: CORE DATA

PROXY DATA: BENTHIC FORAMS

PROXY DATA: PLANKTONIC FORAMS

STABLE ISOTOPES OF OXYGEN OXYGEN: 8 protons/8 neutrons At. Mass = 16 Isotopes: variants in nature that have more or less neutrons than the norm (dominant) In the natural world the Standard Mean Ocean Water (SMOW) today contains 2 atoms of Oxygen that have 8 protons and 10 neutrons = mass 18 for every 1000 atoms of “normal” oxygen – mass 16. This is measured as the del (delta = difference) of that isotope to the norm: i.e. δO 18 = 2 o / oo and measurements are in reference to SMOW

STABLE ISOTOPES OF OXYGEN IN SEA WATER H 2 O OXYGEN in sea water: in reference to SMOW = positive in glacials (more ice) = negative farther back in time (less ice) PROBLEM: no fossil sea water; therefore we rely on measurements from CaCO 3 from foram shells, etc. that are in equilibrium with sea water (i.e. proxy data)

ISOTOPIC FRACTIONATION

WHAT CAN INFLUENCE OXYGEN ISOTOPIC RATIOS IN CaCO 3 1: Ice Volume (salinity) – up to 2 o / oo SMOW: 1 o : Ice Volume (salinity) – up to 2 o / oo SMOW: - a result of preferentially evaporating H 2 16 O from the ocean and accumulating it as ice on land (up to 100m worth of the ocean water) – thus enriching the oceans in H 2 18 O 1: Temperature = ~+0.25 o / oo per drop of a o C 1 o : Temperature = ~+0.25 o / oo per drop of a o C

OXYGEN ISOTOPIC RATIO INFLUENCES IN CaCO 3 Local Salinity: ocean / fresh water / proximity to rivers, etc. Species habitat: where in the water column do they live (temp/salinity) 2 INFLUENCES: 2 o INFLUENCES: Species fractionation: a poorly understood process

ICE CORE DATA EMPIRICAL DATA: Gas bubbles = % CO 2, % O 2, %N 2, etc. Compare: actual measurements you can compare to values today PROXY DATA: δO 18, δC 13, δH 2,(deuterium), etc. from H 2 O and correlate it to CaCO 3 from Ocean samples Interpret: e.g. δO 18 : ice volume, temperature, salinity EMPIRICAL AND PROXY DATA

ICE CORES

Brook, 2008 Nature Empirical Interpreted

Wikipedia Proxy data: stable isotopes

- SO – WHAT CONTROLS CLIMATE

Gerhard et al., 2001

Rohling, et al., (PALAESENS Project mbrs), o Forcings Solar Luminosity Atm. Comp. 2 o Forcings Continents (latitudes & elevations) Ocean circulation weathering CO 2 3 o Forcings Obliquity Precession Eccentricity CO 2 /CH 4 FEEDBACKS 4 o Forcings Volcanic eruptions Sunspots Cycles El Nino/ La Nina Cloud Solar storms

Milankovitch cycles (forcing factors)

But it’s also CO2 and here’s the geologic proof: CASE STUDIES: 1.The Paleocene-Eocene Thermal Maximum (PETM) whereby CO 2 increased dramatically and climate warmed dramatically as well 2.The Azolla event whereby CO 2 dimished dramatically – yet temperature didn’t at much – it’s still being studied

The PETM

PETM - THE LAND RECORD

Bighorn Basin PETM interval in fluvial deposits with excellent alluvial paleosols - seen as color bands, which are soil horizons Found in Willwood Fm Reds, purples due to iron oxides in B horizons

Paleosol Density Pre-PETM PETM

Bighorn Basin Climate Plant fossils and isotopes show Mean Annual Temperature of 20 o to 25 o C or 68 to 77 o F Similar to Gulf Coast region today

The Azolla event

the massive decrease in atmospheric CO2? Bujak, pers. Comm. UNPRECEDENTED DROP IN CO 2

Eocene: 800,000 years of sequestration of Azolla organic matter Slower rates of plate tectonics = lower recycling of carbonate = reduction of CO 2 in atmosphere So what caused the drop in CO2 in the Eocene and since?

P/E World No Polar Ice Caps From Blakey (2007)

ARCTIC EVENTS PROXY DATA Brinkhuis et al,, 2006 Moran et al., 2006

ACEX Azolla core >8 metre ACEX core with 90% Azolla Azolla occurs as laminated layers indicates Azolla deposited in situ bottom-water anoxia at ACEX site Bujak, pers. Comm.

the massive decrease in atmospheric CO2? Bujak, pers. Comm. UNPRECEDENTED DROP IN CO 2

The longer record

THE PRESENT So what’s going on today? What’s going to happen in the short-term?

Today’s Unique Event: Anthropogenic Global Warming Today CO 2 for the past 400 ky Pliocene levels of 400ppm

1946 – 1950 svs.gsfc.nasa.gov

Temperature svs.gsfc.nasa.gov

Arctic Sea Ice Extent If sea-ice continues to contract rapidly over the next several years, Arctic land warming and permafrost thaw are likely to accelerate. David Lawrence, NCAR Satellite imagery of sea ice extent in September 1979, and at a record low in September Source: NASA

Wikipedia Solar irradiance: 680 W/m 2 Solar irradiance: 342 W/m 2

Expected levels of CO2 around 2100 for business as usual

I refer you to Jeff Masters PowerPoint or PDF entitled: Earth's Climate: Where are we at, and where are we headed (click here: PowerPoint-11Mb or PDF- 4Mb)PowerPoint-11MbPDF- 4Mb 6 slides follow

Correcting for El Niño and La Niña Influences Shows the Global Warming Trend More Clearly

How to Abuse Statistics: Choose a Short Time Interval and Ignore the Long-Term Trend